1. Field of the Invention
The present invention relates to an arrangement for transferring castable material without pipes or conduits from a feeding means to a destination, particularly in underground mining. The arrangement includes a radially open centrifugal wheel which rotates about an axis and has essentially radially extending blades. The arrangement further includes a housing belt. The material is axially supplied to the centrifugal wheel and is radially discharged therefrom.
2. Description of the Related Art
In a known arrangement of the above-described type, the feeding means is a hopper arranged above the central portion of the centrifugal wheel. The material to be transferred is conducted from the hopper into the centrifugal wheel through an eccentrically arranged segment-like opening in the bottom of the hopper. The centrifugal wheel has an upper annular disk whose central recess corresponds to the diameter of the lower end of the hopper. The closed bottom of the centrifugal wheel is arranged spaced apart from the annular disk. The closed bottom has, in the center thereof, an essentially conical deflection hub which extends over about 3/4 of the height of the centrifugal wheel. The surface of the deflection hub is concavely curved. The annular disk and the bottom of the centrifugal wheel are spaced apart from each other by straight blades which extend from the circumference of the centrifugal wheel over about 1/4 of the diameter of the centrifugal wheel. The blades are arranged inclined at an angle relative to a plane which extends from the circumference of the centrifugal wheel through the axis of rotation of the centrifugal wheel.
A housing belt is provided at the circumference of the centrifugal wheel. The housing belt is guided around altogether six guide rollers, two of which guide rollers form the lateral borders of a discharge portion of the centrifugal wheel. One of these rollers at the border is constructed as a drive for the housing belt and this roller simultaneously serves as the drive for the centrifugal wheel.
The centrifugal wheel and the housing belt are mounted in a housing whose curved side wall partially also surrounds the guide rollers which form the borders of the discharge portion.
The material, which is eccentrically fed through the hopper under gravity into the centrifugal wheel, is deflected at the deflection hub into the plane of the centrifugal wheel and is displaced by the blades as a result of the influence of centrifugal force toward the housing belt. The material is taken along by the housing belt and is subsequently radially discharged through the discharge portion.
The known arrangement has the disadvantage that the material is introduced eccentrically into the centrifugal wheel and, thus, the material cannot be aligned in a defined manner at the inlet side. Rather, the material initially slides through, relative to the bottom of the centrifugal wheel and is then contacted by the blades at a location which cannot be predetermined and is moved in an uncontrolled manner, and without directions in the entire region of the centrifugal wheel, so that damage to the arrangement cannot be avoided.
However, the region which is subjected to the most severe impact-like loads is the region in which the housing belt is pressed again at the centrifugal wheel. Moreover, very high shear loads are unavoidable when the circumferential edge of a blade comes again into contact with the housing belt and material components are clamped at that moment between the blade edge, the guide roller and the housing belt. As a consequence, the service life of the flexible housing belt is very limited. In addition, the drive of the housing belt can also not prevent relative movements of housing belt and centrifugal wheel in the case of slight jams. These relative movements also lead to an increased wear.